This invention relates to refrigerators, cool chambers and other such enclosures for the safe-keeping and preservation of foodstuff, and more particularly to refrigerated, open-top food displays and counter top buffets.
Open-top, refrigerated food containers are commonly found on display units of self-service stores, in counter tops of self-service restaurants and the kitchen of restaurants. Dishes offering a variety of fares or food ingredients are placed in the shallow well of the container so they can be easily accessed by the customer or food preparator. Keeping the food dishes, buckets or pans and their contents refrigerated while in such an open top device has always been problematic. Most refrigerated food pans of the prior art uses the same cooling techniques used in refrigerators which consists in running a cooling expansion coil in a circuitous pattern in close contact with the bottom and wall of the pan. While this system maintains a relatively low temperature within the confines of the pan, it relies on temperature transfer from the expansion coil to the lining of the pan, to the container and finally, to the food item. The dishes may be made of synthetic or earth materials with relatively poor coefficient of heat transfer. Delay between the placement of the food container into the pan and cooling of the food may be longer than the time it takes the customers to empty the container. Many refrigerated food displays, notably those used in the kitchens of restaurants to hold the ingredients of dishes being prepared, consist of refrigerated cabinets having a large cut-out in the top. Containers are supported over this open top by a series of rails. The flow of cooling air is generated and often extends into the lower part of the cabinet as taught by U.S. Pat. No. 5,168,719 Branz et al. The cooling effect of this type of device is seriously affected every time the front door of the cabinet is opened to get access to items stored therein. Another prior art approach has been to divide the food pan into separate compartments by refrigerated partitions. This last solution imposes limits upon the type, number and arrangement of the containers within the pan.
The instant invention results from an attempt to devise a more efficient open-top food display.
The principal and secondary objects of this invention are to provide an open-top refrigerated shallow food pan suitable for holding a number of food dishes, or other containers and rapidly bringing and keeping their contents to a relatively low, even temperature for preserving the integrity and taste of the foodstuff.
Another object of this invention is to provide a compact open-top food pan refrigerated by a flow of cooled air generated and distributed by a structure that does not extend below the bottom level of the pan.
It is also an object of this invention to provide an efficient open-top, refrigerated food pan which is relatively easy to clean, service and repair.
These and other valuable objects are achieved by an open-top food pan that comprises an inner liner including a flat and unpunctured bottom plate and a relatively shallow peripheral wall integrally and seamlessly made of a material having a high coefficient of thermal transfer such as a metal; and an outer shell which is spaced apart from the liner to define a space therebetween. That space if first occupied by a chamber housing a mechanism that provides a source of pressurized cold fluid, either gas or fluid mist, and preferably air. The chamber is directly accessible by removal of a panel in the wall of the liner. The part of the interspace not occupied by the chamber is filled with insulating material such as injected and expanded styrofoam. One axial end of the chamber is connected to a blower which sucks air from an opening in the wall of the liner and axially forces it across a spirally coiled expansion cooling duct. The opposite end of the chamber is connected to a manifold running peripherally between the liner and the outer shell near the upper rim of the pan. A series of exit ports along the manifold are sized and oriented to discharge the cold fluid across the upper region of the pan. No part of the cooled air generating and distributing apparatus extends below the bottom level of the pan.
A second expansion cooling duct is run along a circuitous path within the interspace and in intimate contact with the bottom and wall of the pan. Food to be displayed in the pan is preferably placed in individual containers with upper rims rising slightly above the level of the cold air exit ports so that the cooling fluid can be forced between the containers for a more rapid and efficient cooling of the foodstuff.